Inhibition of the formation of the neurotoxin 5-S-cysteinyl-dopamine by polyphenols.

Abstract

The death of nigral neurons in Parkinson's disease is thought to involve the formation of the endogenous neurotoxin, 5-S-cysteinyl-dopamine. In the present study, we show that the polyphenols, (+)-catechin and caffeic acid, which contain a catechol moiety, inhibit tyrosinase-induced formation of 5-S-cysteinyl-dopamine via their capacity to undergo tyrosinase-induced oxidation to yield cysteinyl-polyphenol adducts. In contrast, the inhibition afforded by the flavanone, hesperetin, was not accompanied by the formation of cysteinyl-hesperetin adducts, indicating that it may inhibit via direct interaction with tyrosinase. Whilst the stilbene resveratrol also inhibited 5-S-cysteinyl-dopamine formation, this was accompanied by the formation of dihydrobenzothiazine, a strong neurotoxin. Our data indicate that the inhibitory effects of polyphenols against 5-S-cysteinyl-dopamine formation are structure-dependent and shed further light on the mechanisms by which polyphenols exert protection against neuronal injury relevant to neurodegenerative diseases.

• Authors: David Vauzour, Katerina Vafeiadou, Jeremy P E Spencer
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 362 Issue 2 Pg. 340-6 (Oct 19 2007) ISSN: 0006-291X [Print] United States
• PMID: 17716620 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Flavonoids
• Neurotoxins
• Phenols
• Polyphenols
• 5-S-cysteinyldopamine
• Monophenol Monooxygenase
• Dopamine

Topics

• Chromatography, High Pressure Liquid
• Dopamine (analogs & derivatives, chemistry, metabolism)
• Flavonoids (chemistry, pharmacology)
• Mass Spectrometry
• Monophenol Monooxygenase (antagonists & inhibitors, chemistry, metabolism)
• Neurotoxins (antagonists & inhibitors, chemistry, metabolism)
• Phenols (chemistry, pharmacology)
• Polyphenols